title: Bone is more susceptible to vitamin K deficiency than liver in the institutionalized elderly.
abstract: In Japan, γ-carboxylation of blood coagulation factors is the basis for determining adequate intake (AI) for vitamin K in Dietary Reference Intakes (DRIs) issued in 2010. Recently, vitamin K is also known to be essential for preventing fracture. In this study, relative susceptibility of liver and bone to vitamin K deficiency was studied. Thirty-seven elderly institutionalized subjects were evaluated for vitamin K status by measuring serum PIVKA (protein induced by vitamin K absence) -II and ucOC (undercarboxylated osteocalcin) levels, as sensitive markers for hepatic and skeletal vitamin K deficiency, respectively. Serum PIVKA-II and ucOC levels, with their cut-off values in the parentheses, were 20.2±8.9 mAUmL (28 mAU/mL) and 4.7±3.0 ng/mL (4.5 ng/mL), respectively. Median vitamin K intake was approximately 200 μg/day, which is more than 3 times higher than the current Japanese AI. Vitamin K intake was significantly correlated with serum PIVKA-II and ucOC/OC levels, but not with serum ucOC level. Although serum ucOC level is generally a good indicator for vitamin K status, multiple regression analysis revealed that elevated bone turnover marker significantly contributed to serum ucOC level. All subjects had vitamin K intake exceeding AI for vitamin K. Nevertheless, serum PIVKA-II and ucOC concentrations exceeded the cut-off value in 14% and 43% of subjects, respectively. The present findings suggest that vitamin K intake greater than the current AI is required for the skeletal health in the institutionalized elderly.
authors.affiliation: Department of Food and Nutrition, Kyoto Women's University, 35, Imakumano-kitahiyoshicho, Higashiyama 605-8501 Japan.
authors.forename: Akiko
authors.initials: A
authors.lastname: Kuwabara
authors.forename: Minori
authors.initials: M
authors.lastname: Fujii
authors.forename: Nobuko
authors.initials: N
authors.lastname: Kawai
authors.forename: Kunihiko
authors.initials: K
authors.lastname: Tozawa
authors.forename: Shoko
authors.initials: S
authors.lastname: Kido
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Tanaka
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood; D001842:Bone and Bones / Q000737:chemistry*; D004032:Diet; D058620:Elder Nutritional Physiological Phenomena; D002149:Energy Intake; D005260:Female; D050723:Fractures, Bone / Q000209:etiology; D006707:Homes for the Aged; D006801:Humans; D008099:Liver / Q000737:chemistry*; D008107:Liver Diseases / Q000209:etiology; D008297:Male; D009735:Nursing Homes; D015675:Osteocalcin / Q000097:blood; D011498:Protein Precursors / Q000097:blood; D011516:Prothrombin; D014812:Vitamin K / Q000008:administration & dosage; D014813:Vitamin K Deficiency / Q000097:blood* / Q000150:complications
chemical_list: D015415:Biomarkers; D011498:Protein Precursors; D015675:Osteocalcin; D014812:Vitamin K; C008208:acarboxyprothrombin; D011516:Prothrombin